Method of and apparatus for removing and burning or chemical uttlization of convertergases, particularly during the fining process of crude-iron with oxygen



Nov. 19, 1963 s. HOFF METHOD OF AND APPARATUS FOR REMOVING AND BURNING 0R CHEMICAL UTILIZATION OF CONVERTER GASES, PARTICULARLY DURING THE FINING PROCESS OF CRUDE-IRON WITH OXYGEN 2 Sheets-Sheet 1 Filed Feb. 21, 1961 Nov. 19, 1963 H. s. HOFF 3,111,400

METHOD OF AND APPARATUS FOR REMOVING AND BURNING 0R CHEMICAL UTILIZATION OF CONVERTER GASES, PARTICULARLY DURING THE FINING PRocEss OF CRUDE-IRON WITH OXYGEN Filed Feb, 21, 1961 2 Sheets-Sheet 2 F 1g. 2

Jnvemar:

United States atent O The present invention relates to a method of and apparatus for removing, burning or chemical utilization of converter gases, particularly during the fining of crudeiron with oxygen.

The gases produced during the fining process of carboncontaining iron by blowing oxygen thereon, which gases are rich in carbon monoxide, have been caught before, by mounting a head on the orifice of the converter and fed through a conduit fastened to the head for cleaning of the gases from dust, as well as for combustion or chemical utilization thereof. It was not possible, however, to provide until now a sealing between the converter and the head mounted thereon in a satisfactory manner so that the penetration of air and the emergence of converter gases are prevented to a sufficient extent. Due to the entrance of air, a portion of the valuable CO gases are needlessly burned, and the danger of explosions or detonations is increased.

It is one object of the present invention to provide a method of removing and burning or chemical utilization of converter gases which avoids the drawbacks of the known methods.

It is another object of the present invention to provide a method of removing and burning or chemical utilization of converter gases wherein the converter gases are caught in a water cooled head mounted over the converter orifice and wherein the penetration of air in the slot formed between the head and the converter is extensively prevented by a gas stream passing the slot.

The extensive prevention of access of air to the emerging converter gases is of particular importance, if the gases are burned for utilization of their calorific value without prior dust removal. While until now to an appreciable part the air, which enters through the slot between the converter and the converter head, is used as combustion air for the combustion of the gases in a combustion chamber and a converter chimney, respectively, which chimney can be formed as a steam boiler, in accordance with another object of the present invention a method of removing and burning or chemical utilization of converter gases is provided, wherein the combustion air is fed to the converter gases, which have been caught without addition of appreciable amounts of air, exclusively as blown air.

In the known method of operation, wherein a suction blower, which is disposed behind the dust removing device, draws the gases through the combustion chamber and through the dust removing device, the amount of air drawn in between the converter and the combustion chamber cannot be dosed exactly, because in case of an insufficient motion effect, the danger exists that the emerging gases enter the workshop. On the other hand, the exact dosage of the combustion air is important in view of the changing quantity during the blowing period, because the latter controls the quantity of the emerging gases, the combustion temperature, and, thereby, also the humidity content of the gases from which the dust is to be removed, in case of a direct cooling provided prior to the 3,111,4M Patented Nov. 19, 1963 ice dust removal by injection of water. It is, therefore, one aim to bring the air-surplus number to such value over the entire blowing period, which value, on the one hand, brings about a best value for the amount of emerging gases, and on the other hand, the most favorable value for the desirable and permissible, respectively, combustion temperature. This end is obtained in accordance with the present invention by the feeding of combustion air by means of blowers, whereby an exact control of the air quantities is possible by known means.

This kind of air feeding can be chosen freely as to the place of application and can be performed in practically any suitable manner. Thus it is possible, for instance during utilization of the emerging gases in steam vessels, to adjust not only the most favorable combustion temperature for the vessel, but also to provide air feeding at several places and thus to distribute correctly the calorific effect over the entire vessel. The feeding of combustion air as blow air is not only applicable, if the calorific value of the emerging converter gases is utilized in steam vessels, but for each utilization of the combustion heat of the emerging gases burned prior to the dust removal.

With these and other objects in view which will become apparent in the following detailed description, the present invention will be clearly understood in connection with the accompanying drawings, in which:

FIGURE 1 is a schematic section of a converter with a device for removal of the converter gases and with a conduit for feeding away the converter gases; and

FIGS. 2 and 3 are fragmentary sections of two embodiments of a head member mounted on the converter above its orifice.

Referring now to the drawings, and in particular to FIG. 1, the apparatus comprises a converter 1 and a head structure over the orifice of the converter 1 and includes a first water-cooled head member 2 adapted for removal of the converter gases. The head structure includes a second head member 3 which is disposed outside of the first head member 2, the inner chamber 4, defined by the second head member 3, being selectively subjected to pressure below atmospheric pressure or to pressure above atmospheric pressure by means of the conduit 5 terminating in the chamber 4. If the air is withdrawn from the chamber 4 through the conduit 5 and the chamber 4 is thus subjected to pressure below atmospheric pressure, an air stream is formed which enters into the annular slot 6, formed between the inner head member 2 and the outer head member 3. Upon providing pressure above atmospheric pressure in the chamber 4, an air or gas stream escapes through the annular slot 6. Both gas streams prevent extensively the entrance of air through the slot 7 defined between the converter 1 and the first head member 2 into the inner space of the head member 2. The gases emerging from the converter 1 enter the first head member 2 and are fed into the likewise watercooled conduit 8 and then into the conduit 9. The conduit b can be moved upwardly and downwardly jointly with the head member 2 by means of the hydraulic device ltl, whereby the wave tube 11 functions as an elastic connection with the further gas removal conduit 9. The oxygen jet 12 serves the purpose to blow oxygen onto the metal bath disposed in the converter 1.

Referring now to FlGS. 2 and 3 of the drawings, the two embodiments disclosed in FIGS. 2 and 3 have an outer head member 3 which projects downwardly be yond the lower edge of the inner head member 2. The other elements, bearing the same numerals as indicated in FIG. 1, are identical with the embodiment shown in FIG. 1 and do not need repetition. Thus it will be readily found that the embodiment of the head member 2, shown in FIG. 2 of the drawings, differs from the embodiment disclosed in FIG. 1 of the drawing merely by the arrangernent according to which the outer head member 3 projects beyond the lower edge of the inner head member 2. The same applies also for the head member 3, shown in EEG. 3 of the drawings, which is, however, additionally equipped with a sealing ring 13, which seals oil the slot between the outer head portion 3 and the converter 1.

The operation of the apparatus described above takes place, for instance, in the following manner:

Upon blowing of oxygen through the jet 12 onto the crude-iron bath, disposed in the converter 1, gases rich in CO and of a hi h temperature are formed due to the combustion of carbon.

The gases emerge from the converter 1 into the head member 2. A pressure below atmospheric pressure is created in the inner space or chamber 4 of the outer head member 3 by corresponding drawing of air through the conduit 5, so that air is drawn in through the slot 6. Thus as annular air stream is formed in front of the slot '7, which exerts, upon corresponding formation of the faces of the head member 2 surrounding the slot 7 and of the converter 1, a slight suction effect opposite the slot 7, which suction efiect prevents practically completely the entrance of air through the slot 7 into the head member 2.

It has been found during experiments with the head structure, as disclosed in FIG. 1 of the drawings, that the removed converter gases have a higher CO-content upon creating the mentioned annular air stream, as compared, when Working without the annular air stream. The oxygen content of the gases did not rise in the head member 2 over a few percent and amounted to less than 1% over a great part of the blowing period. The CO content in the head member 2 was changed only negligibly compared with that of the converter 1. It results therefrom, that an afterburning from C to CO has been prevented to a large extent.

During the greatest part of the blowing period, the CO-content or the converter gases amounts to more than 50% and up to 96%, so that many possibilities exist for utilization of the gases due to their calorific value. Yet, the gases are also suitable for utilization for the manufacture of chemical material due to their low dilutions by air.

Since the after-burning can be avoided to a great extent, the temperatures of the emerging gases are reduced during the method performed in accordance with the present invention. By such arrangement, the required temperature reduction by means of indirect cooling can be limited to the cooling necessary for the control of the slopping and the radiation or" heat from the converter 1.

Since the sealing against atmospheric air between the converter 1 and the head member 2 is brought about by a gas stream, a tight engagement of the head member 2 on the converter 1 is not required. Rather, it is possible to have a slot between the converter 1 and the head member 2. Even during heavy removal of material by slopping, the shape or" the parts of the head member 2 which limit the slot and which are disposed adjacent thereof, are maintained to a sufficient extent, since the material removed from the converter bursts oil and runs off, respectively. An adherence of the material removed from the converter above the head of the converter is of no importance for the operation of the sealing obtained in accordance with the present invention, since this sealing is influenced only by the outer edge of the converter head and the head member 2. These faces remain clean, however, during the operation.

As it has been already stated, it is possible to provide in the device, shown in FIG. 1 of the drawings, pressure above atmospheric pressure inside of the outer head member 3 and to cause the closure of the slot 7 by means of an air stream emerging from the slot 6. Instead of air, another gas can be used, for instance nitrogen originating from the oxygen-producing device. The embodiment dis- '4; closed in FIG. 1 has the advantage over the embodiments shown in F165. 2 and 3, that the converter flame may be observed.

The devicesdisclosed in FIGS. 2 and 3 are less suitable for the application of pressure above atmospheric pressure in the chamber 4, if air is used for the formation of the closing gas stream. On the other hand, the embodiments of the head structure, as disclosed in FIGS. 2 and 3, with a deeply lowered head member 3 are suitable for the use of nitrogen or blast furnace gases under pressure above atmospheric pressure. Furthermore, blast furnace gases can be admixed as a cooling gas to the gases emerging from the converter, particularly in the embodiment disclosed in FIG. 3 of the drawings.

The described apparatus shows a way, how converter gases a high Oil-content may be removed without disturbances and without dangerous detonations and how they can be applied to combustion and to utilization, respectively, at a place provided therefor without requiring particular additional devices, as gas-locks, or the like. Furthermore the apparatus provides the possibility to dose exactly the combustion air during the utilization of the heat of combustion of the emerging gases and to feed the combustion air just to those places, at which the heating effect has to take place. i

While I have disclosed several embodiments of the present invention, it is to be understood that these embodiments are given by example only and not in a limiting sense, the scope of the present invention being determined by the objects and the claims.

I claim:

1. A method of removal of converter gases generated in and emerging from a converter having an orifice into a conduit, the latter including an inner head member disposed adjacent said orifice of said converter and defining an annular slot between the latter and said inner head member, arr outer head member surrounding said inner head member at the free end of the latter and defining a chamber between said inner and outer head members, and a conduit leading into said chamber, comprising the step of passing a gas stream of a pressure different from that of said gases emerging from said converter through said chamber and past said slot in order to substantially prevent penetration of air into and emergence of said converter gases from said converter through said annular slot.

*2. The method, as set forth in claim 1, which includes the step of feeding blown air exclusively as combustion air into said converter gases, said combustion air being adapted for the combustion of said converter gases.

3. The method, as set forth in claim 2, wherein said blown air is applied at different points in a plurality of portions.

4. The method, as set forth in claim 2, wherein said combus ion or" said converter gases is performed without prior removal of dust from said converter gases and which includes the step of indirect cooling in order to withdraw heat from said converter gases.

5. The method, as set forth in claim 1, wherein said gas stream comprises nitrogen.

6. The method, as set forth in claim 1, wherein said gas stream comprises blast furnace gases.

7. An apparatus including a converter for removal and burning or chemical utilization of gases generated in and emerging from said converter having an orifice comprising a head structure disposed slightly spaced apart from said orifice of said converter and defining Ia first annular slot between said converter and said head structure, the latter comprising an inner head member having an open diameter substantially equal with that of said orifice, an outer head member surrounding said inner head member and defining a chamber therebetween, said chamber opens ing downwardly to form a second annular slot between said inner head member and said outer head member, means connected with said outer head member and adapted to pass gases of a pressure difierent from that of said converter gases through said chamber.

8. The apparatus, as set forth in claim 7, wherein said means connected with said chamber comprises a conduit communicating with said chamber defined in said outer head member.

9. The apparatus, as set forth in claim 7, wherein said outer head member projects downwardly beyond the lowermost portion of said inner head member and beyond the upper edge of said converter.

10. The apparatus, as set forth in claim 9 wherein said outer head member comprising an outer, substantially vertically extending Wall, the upper end of said Wall being secured to said head structure and the lower end of said Wall having gas stream sealing means disposed about the upper portion of said converter and sealing ofi said second annular slot, in order to close said chamber.

References Cited in the file of this patent UNITED STATES PATENTS 2,855,292 Vogt Oct. 7, 1958 FOREIGN PATENTS 768,632 Great Britmn Feb. 13, 1957 772,632 Great Britain Apr. 17, 1957 1,063,191 Germany Aug. 13, 1959 

1. A METHOD OF REMOVAL OF CONVERTER GASES GENERATED IN AND EMERGING FROM A CNVERTER HAVING AN ORIFICE INTO A CONDUIT, THE LATTER INCLUDING AN INNER HEAD, MEMBER DISPOSED ADJACENT SAID ORIFICE OF SAID CONVERTER AND DEFINING AN ANNULAR SLOT BETWEENTHE LATTER AND SAID INNER HEAD MEMBER, AN OUTER HEAD MEMBER SURROUNDING SAID INNER HEAD MEMBER AT THE FREE END OF THE LATTER AND DEFINING A CHAMBER BETWEEN SAID INNER AND OUTER HEAD MEMBERS, AND A CONDUIT LEADING INTO SAID CHAMBER, COMPRISING THE STEP PASSING A GAS STREAM OF A PRESSURE DIFFERENT FROM THAT OF SAID GASES EMERGING FROM SAID CONVERTER THROUGH SAID CHAMBER AND PAST SAID SLOT IN ORDER TO SUBSTANTIALLY PREVENT PENETRATION OF AIR INTO AND EMERGENCE OF SAID CONVERTER GASES FROM SAID CONVERTER THROUGH SAID ANNULAR SLOT. 